Many types of electrochemical cells utilize a liquid ionically conductive medium to support electrochemical reactions within the cell. For example, a metal-air electrochemical cell system may comprise one or more cells, each having a fuel electrode serving as an anode at which metal fuel is oxidized, and an air breathing oxidant electrode at which oxygen from ambient air is reduced. The liquid ionically conductive medium in such cells may communicate the oxidized/reduced ions between the electrodes.
In some electrochemical cell systems, various gasses may evolve during the charging and/or discharging of the cell. Such gasses may be harmful to the cell, and may damage or impede performance of the cell. For example, in some cases the cell may be harmed due to the evolved gasses increasing pressure within a confined area in the cell. In some cases, the cell (and potentially its surroundings) may be harmed due to the evolution of a potentially volatile gas or combination of gasses. As such, some electrochemical cells are configured to disperse such gasses by including vents therein, so that gasses may escape into the ambient environment. For example, U.S. patent application Ser. No. 13/566,948, incorporated herein in its entirety by reference, discloses a membrane gas vent configured to disperse gases out of an electrochemical cell. Other electrochemical cells may be configured with pressure relief valves, which are typically closed, however open when the pressure within the cell exceeds a threshold amount.
Among other improvements, the present application also endeavors to provide an effective and improved way of controlling the discharge of gasses within the cell without adversely affecting the flow of liquid electrolytes within the cell and/or the performance of the cell during operation.